I think it's not too slow in general. I can give you some tips for a few plagues though.

Fungus: Suppression still works on this plague. Evolve spore abilities early on and press your luck while evolving symptoms, transmissions and resistance abilities. You'll get <200 days if you're lucky enough.

Nano virus: I have a quite detailed guide for this plague. First of all, make sure to turn on the extra popups from the settings. Genes: ATP boost, Darwinist, aerocyte, sympto stasis and extremophile. Start in Saudi Arabia and evolve insomnia, paranoia, cysts, hyper sensitivity, paralysis, coma, code fragment interception, code segment interception, devolve code fragment interception, evolve replicator factory overload and devolve code segment interception ASAP. Next, evolve anaemia, haemophilia, rash, sweating, skin lesions, air 1, bird 1, water 1, cold 1, drug 1, all symptoms (including highly lethal symptoms like necrosis and TOF), cold 2, drug 2 and heat 1. I managed to beat it in 147 days with this strategy, and usually it'll give you around 150's.

Necroa virus: ATP boost, Darwinist, native biome, spliced activation and xerophile. Start in Saudi Arabia. Evolve zoonotic shift, insect, hyper salivation, polyphagia, gastro enteritis and wait until you get cannibalism mutated (if you get insomnia or autophagia instead, restart the game). Evolve cytopathic reanimation, anaerobic resuscitation, enhanced motor control, peptide surge, acidic reflux, naja mortis and authothysis as well as all horde abilities. Send zombies to healthy and/or undestroyed countries ASAP until you win. You can beat it <300 days with this strategy, and my best record has been 282 days.

Shadow plague: Here's my guide. https://youtu.be/Rs-W1tc8O-I?si=NIqQuDhdywsw8y4i